Donald Trump’s campaign said Tuesday night that the Republican presidential primary front-runner does not plan to participate in the upcoming Fox News/Google debate, shortly after the debate lineup was announced.

Trump’s campaign confirmed the decision to Fox News.

The Republican presidential candidate already had said he probably would not be going, accusing Fox News of “playing games” with him. Trump has cited concerns with one of the debate moderators, Megyn Kelly – but apparently made his decision not to attend following press statements from Fox News.

Trump, though, took heat for his decision from his closest rival in the polls, Texas Sen. Ted Cruz, who accused Trump of being "afraid of Megyn Kelly."

“If Donald is afraid to defend his record, it speaks volumes,” Cruz said in a radio interview with Mark Levin, challenging Trump to a one-on-one debate.

Trump campaign manager Corey Lewandowski told MSNBC’s “Morning Joe” on Wednesday that the boycott had “nothing to do with Megyn Kelly.”

But a half-hour later, Trump again went after Kelly on Twitter, calling her a “lightweight reporter.”

The Fox News/Google debate is set for this Thursday in Des Moines, Iowa. It would mark the first GOP presidential primary debate that Trump has not attended.

His campaign put out a statement Tuesday night confirming the candidate “will not be participating in the Fox News debate and will instead host an event in Iowa to raise money for the Veterans and Wounded Warriors.”

Addressing the matter on “The Kelly File,” Kelly later said: “I’ll be there. … The debate will go on with or without Mr. Trump.”

Despite his complaints, he had easily qualified as one of the eight candidates in the prime-time event.

Fox News announced the candidate lineup for that debate earlier Tuesday evening, and the qualifying participants were:

The lineup reflects a polling boost for Paul, who did not qualify for the most recent Fox Business Network prime-time debate earlier this month, and declined to participate in that program’s evening event.

This time, Paul suggested he’ll attend, saying the campaign is “very excited” about qualifying for the main stage.

Meanwhile, Fox News Chairman Roger Ailes has defended Megyn Kelly amid the criticism from Trump. He issued a statement earlier to The Washington Post saying, “Megyn Kelly is an excellent journalist, and the entire network stands behind her. She will absolutely be on the debate stage on Thursday night."

Kelly has withstood Trump’s attacks since the August debate, when he accused her of purposely attacking him. As part of Trump’s explanation for not participating in Thursday’s debate he called the "Kelly File" host a "lightweight" and "third-rate reporter."

Trump’s campaign manager Corey Lewandowski even threatened to ramp up the verbal attacks Trump has repeated since the first August debate.

“In a call on Saturday with a Fox News executive, Lewandowski stated that Megyn had a ‘rough couple of days after that last debate’ and he ‘would hate to have her go through that again,’” a Fox News statement said late Tuesday.

“Lewandowski was warned not to level any more threats, but he continued to do so. We can’t give in to terrorizations toward any of our employees,” the statement added.

Trump, speaking earlier in Iowa, said he’d probably raise money for veterans instead of doing the event. And speaking with Fox News’ Bret Baier, Trump said he “didn’t like the press releases Fox put out.”

The Fox News/Google debate in Des Moines this Thursday will be the candidates’ last before next week’s Iowa caucuses – which kicks off the Republican presidential nominating process.

In the run-up, the candidates are ramping up their ad spending and shoe-leather campaigning, while going after each other in the process.

After clashing at the most recent GOP debate, Iowa front-runners Trump and Cruz have only turned up their attacks in recent days – particularly as Trump regains his Iowa lead over Cruz in most polls. The race, though, remains close. The latest Quinnipiac University poll showed Trump leading Cruz just 31-29 percent in Iowa.

Cruz said Tuesday that “no state is a must-win for us.” But the reality is his campaign is fighting hard for an Iowa victory, as Trump maintains a huge polling lead in the next contest: the New Hampshire primary.

One new ad from a Cruz-supporting super PAC is accusing Trump of being aligned with Democrats on “government-run health care.” Another from the Cruz campaign returns to the well of criticizing Trump’s “New York values,” while playing a clip of him saying, “How stupid are the people of Iowa?”

Trump, meanwhile, called Cruz a “liar” in an MSNBC interview Tuesday.

“Nobody likes him,” Trump said, attempting to draw a contrast with his own business experience by saying Cruz can’t make a deal with anybody.

The debate on Thursday will be moderated by Fox News anchors Bret Baier, Megyn Kelly and Chris Wallace.

The candidate lineup was decided based on the results of national, New Hampshire and Iowa polling – released before 5 p.m. ET on Tuesday.

To qualify for the prime-time debate, a candidate had to place in the top six in an average of recent national polls, or in the top five in an average of recent Iowa or New Hampshire polls. ‎The evening debate features other candidates who received a minimum 1 percent in at least one recent national poll.